Preparation of Salts.

• Reacting a metal with an acid. • Reacting an insoluble base with an acid. • Neutralising an alkali with an acid by the titration method. • By precipitation.

• add excess base to the acid. • filter to remove any unreacted base that’s been added. • heat the solution to evaporate the water, allowing crystals of the salt to form.

• Measure the alkali into the titration flask using a volumetric pipette. • Add a few drops of indicator solution to the alkali in the flask. • Fill a clean burette with acid. • Record the burette reading. • Open the burette tap and let the acid flow into the flask. • Keep adding acid slowly until the indicator changes color. • Record the reading on the burette.

• Add the metal to the acid in the flask so that the metal is in excess. • Warm the flask gently to complete the reaction. • Filter off the excess metal. • Put the filtrate into an evaporating basin and evaporate the water until the crystalisation point is reached. • Filter off the crystals and wash them with distilled water. • Dry the crystals between sheets of filter paper.

A titration is used to make a soluble salt from an acid. To conduct a titration both acid and alkali must be soluble.

Salts made by the titration method include salts of Group 1 elements and ammonium salts.

The solid obtained when solutions of two soluble compounds are mixed is called a precipitate.

All salts of Group 1 elements. All nitrates. All ammonium salts. Most chlorides, bromides and iodides (halides). Most sulfates. Group I hydroxide and carbonates are soluble. Group I and II oxides react with water.

Chlorides, bromides and iodides of silver and lead. Sulfates of calcium, barium and lead. Most hydroxide and carbonates. Most metal oxides.

making insoluble salts: - mix the two solutions that will form the salt. - filter to remove the solid insoluble salt. - wash salt with distilled water. - leave salt to dry on filter paper.

The ions that do not take part in the reaction are called spectator ions.

• Turns damp red litmus paper blue.

• Bubble the gas through the limewater and it will turn milky (cloudy)

• When damp litmus paper is put into chlorine gas the litmus paper is bleached and turns white.

Use a burning splint held at the open end of a test tube of the gas. ▪ Creates a ‘squeaky pop’ sound.

Uses a glowing splint inserted into a test tube of the gas. ▪ Splint relights in oxygen.

Use aqueous potassium manganate(VII) and there will be a colour change from purple to colourless.

% composition = Ar (X) ÷ Mr (XY) x 100.

A solution in which no more solute will dissolve.